xref: /llvm-project/libcxx/test/std/algorithms/alg.modifying.operations/alg.move/ranges.move.pass.cpp (revision a6e1080b87db8fbe0e1afadd96af5a3c0bd5e279) 
1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 // <algorithm>
10 
11 // UNSUPPORTED: c++03, c++11, c++14, c++17
12 
13 // template<input_iterator I, sentinel_for<I> S, weakly_incrementable O>
14 //   requires indirectly_movable<I, O>
15 //   constexpr ranges::move_result<I, O>
16 //     ranges::move(I first, S last, O result);
17 // template<input_range R, weakly_incrementable O>
18 //   requires indirectly_movable<iterator_t<R>, O>
19 //   constexpr ranges::move_result<borrowed_iterator_t<R>, O>
20 //     ranges::move(R&& r, O result);
21 
22 #include <algorithm>
23 #include <array>
24 #include <cassert>
25 #include <ranges>
26 
27 #include "almost_satisfies_types.h"
28 #include "MoveOnly.h"
29 #include "test_iterators.h"
30 
31 template <class In, class Out = In, class Sent = sentinel_wrapper<In>>
32 concept HasMoveIt = requires(In in, Sent sent, Out out) { std::ranges::move(in, sent, out); };
33 
34 static_assert(HasMoveIt<int*>);
35 static_assert(!HasMoveIt<InputIteratorNotDerivedFrom>);
36 static_assert(!HasMoveIt<InputIteratorNotIndirectlyReadable>);
37 static_assert(!HasMoveIt<InputIteratorNotInputOrOutputIterator>);
38 static_assert(!HasMoveIt<int*, WeaklyIncrementableNotMovable>);
39 struct NotIndirectlyMovable {};
40 static_assert(!HasMoveIt<int*, NotIndirectlyMovable*>);
41 static_assert(!HasMoveIt<int*, int*, SentinelForNotSemiregular>);
42 static_assert(!HasMoveIt<int*, int*, SentinelForNotWeaklyEqualityComparableWith>);
43 
44 template <class Range, class Out>
45 concept HasMoveR = requires(Range range, Out out) { std::ranges::move(range, out); };
46 
47 static_assert(HasMoveR<std::array<int, 10>, int*>);
48 static_assert(!HasMoveR<InputRangeNotDerivedFrom, int*>);
49 static_assert(!HasMoveR<InputRangeNotIndirectlyReadable, int*>);
50 static_assert(!HasMoveR<InputRangeNotInputOrOutputIterator, int*>);
51 static_assert(!HasMoveR<WeaklyIncrementableNotMovable, int*>);
52 static_assert(!HasMoveR<UncheckedRange<NotIndirectlyMovable*>, int*>);
53 static_assert(!HasMoveR<InputRangeNotSentinelSemiregular, int*>);
54 static_assert(!HasMoveR<InputRangeNotSentinelEqualityComparableWith, int*>);
55 static_assert(!HasMoveR<UncheckedRange<int*>, WeaklyIncrementableNotMovable>);
56 
57 static_assert(std::is_same_v<std::ranges::move_result<int, long>, std::ranges::in_out_result<int, long>>);
58 
59 template <class In, class Out, class Sent, int N>
60 constexpr void test(std::array<int, N> in) {
61   {
62     std::array<int, N> out;
63     std::same_as<std::ranges::in_out_result<In, Out>> decltype(auto) ret =
64       std::ranges::move(In(in.data()), Sent(In(in.data() + in.size())), Out(out.data()));
65     assert(in == out);
66     assert(base(ret.in) == in.data() + in.size());
67     assert(base(ret.out) == out.data() + out.size());
68   }
69   {
70     std::array<int, N> out;
71     auto range = std::ranges::subrange(In(in.data()), Sent(In(in.data() + in.size())));
72     std::same_as<std::ranges::in_out_result<In, Out>> decltype(auto) ret =
73         std::ranges::move(range, Out(out.data()));
74     assert(in == out);
75     assert(base(ret.in) == in.data() + in.size());
76     assert(base(ret.out) == out.data() + out.size());
77   }
78 }
79 
80 template <class In, class Out, class Sent = In>
81 constexpr void test_iterators() {
82   // simple test
83   test<In, Out, Sent, 4>({1, 2, 3, 4});
84   // check that an empty range works
85   test<In, Out, Sent, 0>({});
86 }
87 
88 template <class Out>
89 constexpr void test_in_iterators() {
90   test_iterators<cpp20_input_iterator<int*>, Out, sentinel_wrapper<cpp20_input_iterator<int*>>>();
91   test_iterators<forward_iterator<int*>, Out>();
92   test_iterators<bidirectional_iterator<int*>, Out>();
93   test_iterators<random_access_iterator<int*>, Out>();
94   test_iterators<contiguous_iterator<int*>, Out>();
95 }
96 
97 template <class Out>
98 constexpr void test_proxy_in_iterators() {
99   test_iterators<ProxyIterator<cpp20_input_iterator<int*>>, Out, sentinel_wrapper<ProxyIterator<cpp20_input_iterator<int*>>>>();
100   test_iterators<ProxyIterator<forward_iterator<int*>>, Out>();
101   test_iterators<ProxyIterator<bidirectional_iterator<int*>>, Out>();
102   test_iterators<ProxyIterator<random_access_iterator<int*>>, Out>();
103   test_iterators<ProxyIterator<contiguous_iterator<int*>>, Out>();
104 }
105 
106 struct IteratorWithMoveIter {
107   using value_type = int;
108   using difference_type = int;
109   explicit IteratorWithMoveIter() = default;
110   int* ptr;
111   constexpr IteratorWithMoveIter(int* ptr_) : ptr(ptr_) {}
112 
113   constexpr int& operator*() const; // iterator with iter_move should not be dereferenced
114 
115   constexpr IteratorWithMoveIter& operator++() { ++ptr; return *this; }
116   constexpr IteratorWithMoveIter operator++(int) { auto ret = *this; ++*this; return ret; }
117 
118   friend constexpr int iter_move(const IteratorWithMoveIter&) { return 42; }
119 
120   constexpr bool operator==(const IteratorWithMoveIter& other) const = default;
121 };
122 
123 constexpr bool test() {
124   test_in_iterators<cpp17_output_iterator<int*>>();
125   test_in_iterators<cpp20_output_iterator<int*>>();
126   test_in_iterators<cpp17_input_iterator<int*>>();
127   test_in_iterators<cpp20_input_iterator<int*>>();
128   test_in_iterators<forward_iterator<int*>>();
129   test_in_iterators<bidirectional_iterator<int*>>();
130   test_in_iterators<random_access_iterator<int*>>();
131   test_in_iterators<contiguous_iterator<int*>>();
132 
133   test_proxy_in_iterators<ProxyIterator<cpp20_input_iterator<int*>>>();
134   test_proxy_in_iterators<ProxyIterator<forward_iterator<int*>>>();
135   test_proxy_in_iterators<ProxyIterator<bidirectional_iterator<int*>>>();
136   test_proxy_in_iterators<ProxyIterator<random_access_iterator<int*>>>();
137   test_proxy_in_iterators<ProxyIterator<contiguous_iterator<int*>>>();
138 
139   { // check that a move-only type works
140     {
141       MoveOnly a[] = {1, 2, 3};
142       MoveOnly b[3];
143       std::ranges::move(a, std::begin(b));
144       assert(b[0].get() == 1);
145       assert(b[1].get() == 2);
146       assert(b[2].get() == 3);
147     }
148     {
149       MoveOnly a[] = {1, 2, 3};
150       MoveOnly b[3];
151       std::ranges::move(std::begin(a), std::end(a), std::begin(b));
152       assert(b[0].get() == 1);
153       assert(b[1].get() == 2);
154       assert(b[2].get() == 3);
155     }
156   }
157 
158   { // check that a move-only type works for ProxyIterator
159     {
160       MoveOnly a[] = {1, 2, 3};
161       MoveOnly b[3];
162       ProxyRange proxyA{a};
163       ProxyRange proxyB{b};
164       std::ranges::move(proxyA, std::begin(proxyB));
165       assert(b[0].get() == 1);
166       assert(b[1].get() == 2);
167       assert(b[2].get() == 3);
168     }
169     {
170       MoveOnly a[] = {1, 2, 3};
171       MoveOnly b[3];
172       ProxyRange proxyA{a};
173       ProxyRange proxyB{b};
174       std::ranges::move(std::begin(proxyA), std::end(proxyA), std::begin(proxyB));
175       assert(b[0].get() == 1);
176       assert(b[1].get() == 2);
177       assert(b[2].get() == 3);
178     }
179   }
180 
181   { // check that ranges::dangling is returned
182     std::array<int, 4> out;
183     std::same_as<std::ranges::in_out_result<std::ranges::dangling, int*>> decltype(auto) ret =
184       std::ranges::move(std::array {1, 2, 3, 4}, out.data());
185     assert(ret.out == out.data() + 4);
186     assert((out == std::array{1, 2, 3, 4}));
187   }
188 
189   { // check that an iterator is returned with a borrowing range
190     std::array in {1, 2, 3, 4};
191     std::array<int, 4> out;
192     std::same_as<std::ranges::in_out_result<int*, int*>> decltype(auto) ret =
193         std::ranges::move(std::views::all(in), out.data());
194     assert(ret.in == in.data() + 4);
195     assert(ret.out == out.data() + 4);
196     assert(in == out);
197   }
198 
199   { // check that every element is moved exactly once
200     struct MoveOnce {
201       bool moved = false;
202       constexpr MoveOnce() = default;
203       constexpr MoveOnce(const MoveOnce& other) = delete;
204       constexpr MoveOnce& operator=(MoveOnce&& other) {
205         assert(!other.moved);
206         moved = true;
207         return *this;
208       }
209     };
210     {
211       std::array<MoveOnce, 4> in {};
212       std::array<MoveOnce, 4> out {};
213       auto ret = std::ranges::move(in.begin(), in.end(), out.begin());
214       assert(ret.in == in.end());
215       assert(ret.out == out.end());
216       assert(std::all_of(out.begin(), out.end(), [](const auto& e) { return e.moved; }));
217     }
218     {
219       std::array<MoveOnce, 4> in {};
220       std::array<MoveOnce, 4> out {};
221       auto ret = std::ranges::move(in, out.begin());
222       assert(ret.in == in.end());
223       assert(ret.out == out.end());
224       assert(std::all_of(out.begin(), out.end(), [](const auto& e) { return e.moved; }));
225     }
226   }
227 
228   { // check that the range is moved forwards
229     struct OnlyForwardsMovable {
230       OnlyForwardsMovable* next = nullptr;
231       bool canMove = false;
232       OnlyForwardsMovable() = default;
233       constexpr OnlyForwardsMovable& operator=(OnlyForwardsMovable&&) {
234         assert(canMove);
235         if (next != nullptr)
236           next->canMove = true;
237         return *this;
238       }
239     };
240     {
241       std::array<OnlyForwardsMovable, 3> in {};
242       std::array<OnlyForwardsMovable, 3> out {};
243       out[0].next = &out[1];
244       out[1].next = &out[2];
245       out[0].canMove = true;
246       auto ret = std::ranges::move(in.begin(), in.end(), out.begin());
247       assert(ret.in == in.end());
248       assert(ret.out == out.end());
249       assert(out[0].canMove);
250       assert(out[1].canMove);
251       assert(out[2].canMove);
252     }
253     {
254       std::array<OnlyForwardsMovable, 3> in {};
255       std::array<OnlyForwardsMovable, 3> out {};
256       out[0].next = &out[1];
257       out[1].next = &out[2];
258       out[0].canMove = true;
259       auto ret = std::ranges::move(in, out.begin());
260       assert(ret.in == in.end());
261       assert(ret.out == out.end());
262       assert(out[0].canMove);
263       assert(out[1].canMove);
264       assert(out[2].canMove);
265     }
266   }
267 
268   { // check that iter_move is used properly
269     {
270       int a[] = {1, 2, 3, 4};
271       std::array<int, 4> b;
272       auto ret = std::ranges::move(IteratorWithMoveIter(a), IteratorWithMoveIter(a + 4), b.data());
273       assert(ret.in == a + 4);
274       assert(ret.out == b.data() + 4);
275       assert((b == std::array {42, 42, 42, 42}));
276     }
277     {
278       int a[] = {1, 2, 3, 4};
279       std::array<int, 4> b;
280       auto range = std::ranges::subrange(IteratorWithMoveIter(a), IteratorWithMoveIter(a + 4));
281       auto ret = std::ranges::move(range, b.data());
282       assert(ret.in == a + 4);
283       assert(ret.out == b.data() + 4);
284       assert((b == std::array {42, 42, 42, 42}));
285     }
286   }
287 
288   return true;
289 }
290 
291 int main(int, char**) {
292   test();
293   static_assert(test());
294 
295   return 0;
296 }
297